How would you rate the apple pie shown in the photo? Yes, I know the first thing that comes to mind is probably “Disgusting!”, because my food presentation skills are not what they ought to be. (Believe it or not, the apple pie depicted has not been eaten.) But how you assess my efforts must depend on what exactly you’re looking for. (I realise this is kind of obvious, but please bear with me.)

It doesn't LOOK very appetising...For example, if you were grading on taste, I can tell you that this pie was delicious. But if it’s culinary ability you are looking for, I have to confess that the only skills involved were taking it out of the packaging, inserting it into the oven, turning the oven on to the stated temperature, and waiting.

As far as presentation skills are concerned, I agree that now is probably not the time to consider a career change as a waiter – although I have to say, in my defence, that I have not met anyone who can serve up hot apple pie without its falling to bits; I suspect the ones you get in restaurants are sliced up before they are cooked. (Maybe that’s the secret….)

Or you could be looking for the whole package: ability to source the ingredients, make the pastry, etc etc.

Whatever your criteria, two things are clear:

You have to know what they are…
… and so do I.

I don’t see that ICT is any different from apple pies or anything else in this respect. So it seems to me that the following seven things are essential in order to ensure that ICT is assessed properly, ie in a way that is useful to you, your school and, above all, the pupils and their parents:

Agree with colleagues on what it is you wish to measure. That will depend to a large part on the curriculum or scheme of work you follow, but one starting point might be to consider whether you wish to measure ability in skills, such as producing a video, knowledge of techniques, such as knowing a load of keyboard shortcuts or work-arounds, or “digital literacy”, defined in some way.
Ensure that students know what you’re going to be looking for. Perhaps they can even have a say in that, or at least a say in how it will be assessed.
Make sure you don’t confuse a simple skill with a high-level concept (unless you’re only interested in assessing the simple skill, of course.) For example, turning a formula in a spreadsheet into an absolute reference is not, in itself, a big deal. It’s a matter of pressing one key in Excel (F4 since you ask).But I would argue that understanding the concept of an absolute reference, ie knowing what it is and why you might wish to use it, and being able to use it in a particular context, is not quite as easy.
You have to know how to assess skills, knowledge and understanding. You can’t simply judge by appearances – unless the appearance is one of the criteria you’re supposed to be judging. Hence my apple pie example. In my opinion, this is actually quite hard to do in a way that makes it easy to generate numbers in which you can have any great degree of confidence. I think setting well thought-out project work, where you can see what the students do in a particular context, is essential for gaining deep insight into whether they are “thinking ICT”.
Related to the foregoing point, assessment for learning approaches, especially self-assessment, are important too: asking the students what they did, why, how, and whether or not they would do it differently next time. (To be honest, I’m not entirely convinced of the efficacy of peer assessment: see Lessons from the world of sports: #7 The rule of Specialisation.)
And – another AfL “technique” – you have to question the pupils. And wait for an answer. And keep on asking questions. (See 25 ways to make yourself unpopular: #20 Be persistent.)
Finally, set up your lessons so that you can have quality time talking with, and listening to, small groups and individuals. When it comes down to it, talking and listening are pretty effective: as the old British Telecom advert said: “It’s good to talk”!